Bumper extension



FIG. 1 is a left, front perspective view of a bumper extension showing our new design, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is an enlarged top, left, front perspective view thereof;

FIG. 3 is an enlarged left side elevation view thereof;

FIG. 4 is an enlarged top plan view thereof;

FIG. 5 is an enlarged bottom plan view thereof; and

FIG. 6 is an enlarged front elevation view thereof. 

The ornamental design for a bumper extension, as shown and described. 